Fluid pump or injector



Nov. 17, 1959 B. 'r. INSLEY FLUID PUMP OR INJECTOR Filed March 25, 1957INVENTOR. BERT 7'. INSLE Y BY M//z% FLUID PUMP OR INJECTOR Bert T.Insley, Stockton, Calif., assignor of one-half to Brooks Walker, SanFrancisco, Calif.

Application March 25, 1957, Serial No. 648,039

9 Claims. (Cl. 103-120) This invention relates to a method and apparatusfor pumping fluids, liquids or gaseous. More specifically it relates toa means for obtaining controllable injection of fuel, liquid or gaseous,in an engine.

The problem of injecting a precisely timed and accurately meteredquantity of liquid fuel in an engine of either spark ignition orcompression ignition type, poses many difiiculties which in the pasthave been solved primarily through the use of apparatus consisting of alarge number of precision parts. While many such systems of variousdesigns have been utilized with varying degrees of success these systemsare expensive and difficult to manufacture.

The general objective of this invention (in its preferred form), whichmay be combined with auxiliary apparatus for automatically regulatingthe delivery of liquid fuel in conformance with the requirements of theengine and apparatus such as nozzles for inducting the fuel charge, isto provide improved fuel injection apparatus for an engine, and tosimplify the mechanism for accomplishing this result to save cost,weight, and size of equipment required.

A prime object of this invention is to provide a fluid or liquid pumpformed basically of an internal gear mounted on an offset crank pin thatmeshes closely with an internal stationary gear and a plate that ismovable manually relative to said stationary ring gear, and into anexternal cavity to effect the discharge of fuel on each rotation of therotating gear past a given ring gear tooth and when used in an engine toeffect throttling.

Another object of the invention is to provide a small compact structureof symmetrical shape that can be rotated within limits to effect anadvance or retarding of the timing of the injections produced.

A further objective of the present invention is to provide improved fuelinjection apparatus with a minimum number of moving parts which as aconsequence results in lower manufacturing costs, reduced maintenancerequirements and improved reliability. The basic components of thisdesign are adaptable to quantity production by recognized processesincluding gear grinding, powered metal fabrication, die casting, etc.

It is an important objective of this device to provide a variabledelivery positive displacement injection pump which overcomes many ofthe inherent difficulties involved in' injection systems of thecontinuous flow type, timed common rail and conventional timed positivedisplacement systems. With continuous flow or timed common rail systemsaccuracy of metering is limited by the small orifices required which areextremely sensitive to deposits, wear, corrosion, erosion, and otherfactors which affect their metering characteristics. These problems aresolved by the use of positive displacement-type metering elements andalso are solved by the present invention. With even the highest qualityconventional positive displacement systems, however, the multiplicity ofcritical wearing surfaces which affect fuel metering, such as cams,tappets, rollers, links, racks and the like, is largely elim- StatesPatent Ice 2,91

inated by the present device as are the problems associated with wear onthese parts.

A further important objective of the present invention is to eliminateall high speed reciprocating action inherent to injection pumps ofconventional design which include cams, rollers, tappets, wobble plates,racks, etc. Only rotary motion is involved in the basic components ofthis system which makes it adaptable to the high engine speeds ofpresent day engines and projected future designs. As engine speedscontinue to go higher and higher in new designs the problems associatedwith reciprocating-type injection systems will increase. These problemsare eliminated in the present invention.

With almost all other injection systems of the positive displacementtype a transfer pump is required to supply fuel to the injection pumpand an object of the present invention is to eliminate the necessity fora separate transfer pump. It is important to note that the transfer pumpis built into the injection pump and uses the same basic components withonly check valves added to control the flow. The problem of providing anauxiliary transfer pump is therefore solved.

Another objective is to provide a fuel pump system which isself-priming, this being accomplished by the built in transfer pump, afeature which solves the problem of starting the engine when no fuel isinitially present in the fuel system. This must also be done in afashion to purge the system of air or vapor trapped in variouscomponents. In conventional systems purging is a problem because of deadend cavities, voids, passageways, etc. inherent in the design. With thepresent system these vapor traps are eliminated by the basic designwhich includes a vapor eliminating dome freely communicating with thebasic pumping elements. In addition, means may be also included to cutoff the recirculation of fuel back to the tank in order to make the fulldisplacement capacity of the transfer pump portion available to purgefuel lines to the individual injectors. This same cutoff feature may beused as an enrichment device for starting.

It is also the objective of the present system to provide means to matchthe injection rate (the rate during one injection) of the fuel to thevarying requirements of the engine. This problem is solved through theuse of appropriate profiles for the gear teeth, cutoff ports, etc.

Another objective of the present invention is to provide inherentdamping of pressure waves or fluctuations in fuel injection lines,particularly at cutoff of the injection nozzle. These pressure Wavesadversely affect the operation of the nozzle and in conventional systemsrequire the use of critically designed nozzles to obtain desirable flowcharacteristics and clean cutoff with no dribble. At the end ofdelivery, the action of this device is such that an instantaneouspartial vacuum is drawn on the fuel delivery line which cavitates fuelin the line and damps pressure fluctuations. Thus, the problem of nozzledribble due to pressure fluctuations at cutoff are also solved.

.With the present invention the basic design is such that a Wide rangein engine sizes could be accommodated with the interchangeability ofonly a very few parts. This, therefore, solves the problem of providingfor many different sizes.

It is another object of the present invention to provide means toequalize wear effects in the basic elements in order that meteringaccuracy is maintained throughout the life of the pump. This problem issolved by the use of a hunting tooth pinion gear which mates withdifferent teeth in the ring gear in a predetermined sequence dependingon the relative number of teeth on the pinion and ring gears.

Patented Nov. 17, 1959 A further object of this device is to providemeans whereby fuel may be injected into an engine combustion chamber athigh pressures, which are required for head injection systems, withouthigh pressure differentials across the basic metering elements. The useof an external pump to pressurize the present invention to a highpressure but just lower than the nozzle opening pressure allows thebasic metering elements to produce only the additional pressure requiredto satisfactorily operate the nozzle in a positive manner. In some casesthe pressure built up by the transfer pump suction would be sufiicientfor the above, but an additional pressure stage may be obtained wherenecessary, as just described.

As the present invention may also be described as a controllable meansfor pumping liquids a further objective not related to its functions asa fuel injection device is to provide a variable delivery positivedisplace ment pump. Such a pump may be used in hydraulic powertransmission and control devices.

Other features of the invention will be more par ticularly pointed outin the accompanying claims and specifications.

I have illustrated my invention by way of example in the accompanyingdrawings:

Fig. l is a view of one form of the present invention shown inelevation, parts being broken away and parts being shown in sectiontherein taken along the section line 11 of Fig. 2.

Fig. 2 is a top plan view of the apparatus shown in Fig. 1.

Fig. 3 is a horizontal sectional view taken from the plane of thesection line 33 of Fig. 1..

Fig. 4 is a horizontal sectional view taken from the plane of thesection line 44 of Fig. 1.

Fig. 5 is a horizontal sectional view taken from the plane of thesection line 55 of Fig. 1. Figs. 3, 4 and 5 show their respectivesections only, and not piping, etc., which might appear below.

Fig. 6 shows a portion of Fig. 3 enlarged.

Referring now to the above mentioned drawings wherein like numeralsdesignate corresponding parts throughout the various views, 1 is aneccentric shaft, driven at its lower end by suitable means from the camshaft of an internal combustion engine, or by other means where thedevice is used for pumping liquids rather than a fuel injection pump.Eccentric shaft 1 carries the pinion gear 2 eccentrically at its upperend 1a. Pinion gear 2, being thus driven, engages with a stationary ringgear 3 which is attached to pump body 4. Metering control plate 5 isheld in close contact with pinion gear 2 and ring gear 3 by surgechamber housing 6. Thus, the pump body 4, including the ring gear as ineffect a part thereof, cooperates with the surge chamber housing 6 and aretaining plate 12 to define a pump housing, which is divided by theplate 5 into a surge chamber 19 above the plate 5 and a pumping chamberbelow it.

Priming pump section discharge valves 7 are carried by priming pumpdischarge valve plate 8 which is attached by screws to metering controlplate 5. Metering control shaft 9 is attached to metering control plate5 at the lower end and to metering control lever 10 at its upper end,which is limited in its travel by stops 10a.

Intake fuel line 11 is suitably attached to retaining plate 12 andcommunicates with intake valve 13 through intake ports 16a, of which sixare shown in Fig. 5 by way of example. Discharge ports 15, of which sixare shown in Fig. 4, corresponding to a six cylinder engine, eachcommunicate with a delivery valve 17 which delivers metered and timedfuel through tube 28 and suitable means not shown to an internalcombustion engine also not shown.

Pressure regulating valve 18 regulates the pressure in surge chamber 19and is held on its seat by pressure regulating valve spring 20. Thepressure in surge chamber 19 is controlled by pressure regulatingcontrollever 21 which 4 adjusts the tension on pressure regulating valve spring20. Pressure regulating valve 18 may be held rigidly against its seat bypressure regulating valve shutofi pin 22 when pressure regulatingcontrol lever 21 is in the proper position. Excess fuel is returned tothe fuel tank (not shown) through fuel return outlet fitting 23.

Operation Again referring to the drawings described in detail above, theoperation of the present invention may be described in the followingmanner. As the pinion gear 2 rotates within the pump housing in meshwith ring gear 3, a suction (negative pressure) is produced successivelyin the tooth cavities over intake ports 16 as any particular gear toothin ring gear 3 recedes from its mating teeth in pinion gear 2. Thissuction draws liquid fuel into the cavity between gears 2 and 3 throughintake valve 13, of which six are shown. As this action continues thepump housing becomes filled with liquid fuel and after the housing issufficiently filled each tooth of the ring gear 2 will also exertcompressive force on fuel as it goes into mesh with the mating teeth ofthe pinion gear 3 and discharge valve 7 will open and allow liquid fuelor otherwise, to be forcibly displaced into surge chamber 19 which indue course becomes filled with liquid fuel. After surge chamber 19 iscompletely filled with liquid fuel and purged of air and/or vapor,pressure regulating valve 18 will open at a controlled predeterminedpressure and allow excess fuel to be discharged from the fuel returnoutlet fitting 23 which returns fuel to the main fuel tank (not shown).The foregoing describes the action of the self priming transfer pumpsection of the device.

Simultaneously with the action of the transfer pump section timed andmetered fuel in being delivered from the injection section of the deviceto each individual cylinder of the engine (not shown). The action of theinjection portion may be described in the following manner. Startingwith the pump housing and surge chamber filled with liquid fuel and withcontrol plate 5 set in a position which will seal the cavity betweenmeshing teeth at least during part of the time that a particular piniongear tooth is engaging with the meshing ring gear teeth, the fuel in thecavity will be compressed and forced through a particular discharge port15, six of which are shown. This pressure will open delivery valve 17which is connected through suitable means (tube 28) to the fuelinjection nozzle, not shown, in the engine, also not shown. As themetering control lever is positioned by suitable means (not shown)responsive to engine requirements, the control plate 5 rotates andpositions and spill ports 24 so that variable delivery is effected byspilling a controllable portion of fuel trapped in the gear cavitybetween meshing gears. The spilled fuel is retained in the surge chamberand comrningles with the fuel being recirculated back to the fuel tank.Any vapor and/or air released due to turbulence therefore is purged outof the system by recirculation back to the tank which is considered veryadvantageous.

The spill ports 24 are in communication with the outlet ports 15 of thepump only up until the time when the tooth of the pinion 2 engages thewall ofthe cavity of the ring gear 3. Then the spill ports are separatedfrom the outlet ports 15, and, during the remainder of a very shortstroke, the gears 2 and 3 send fuel into the outlet ports 15.

The plate 5 is rotated only in order to vary the cutoif point for thespill ports 24. This movement varies the proportion of fuel pumped intothe fuel-injection outlets 15 relative to the proportion pumped up (atan earlier portion in the cycle) through the spill ports 24. That is theonly purpose of moving the plate 5, and that movement is made to accordwith the fuel consumption of the engine, that is, whether the engine isidling, accelerating, decelerating, or whatever.

It is understood of course that different numbers of valve ports anddelivery ports may be used to accommodate engines with various number ofcylinders and that multiple or single tooth cavities may be used as thevariable displacement volumes for either the transfer pump portion orthe injection pump portion.

During startup or for purging the pressure regulating control lever 21may be positioned so as to shut off the recirculation of fuel back tothe tank. In this case the entire pumping capacity of the transfer pumpportion of the device will discharge continuously through the sixdelivery valves 17 and subsequently to the six cylinders of the engine.As the startup fuel requirement of the engine is relatively large, thegreater throughput from the transfer pump section may be used toadvantage as an enriching (priming or choking) device and may becontrolled by automatic means responsive to engine parameters whichdictate the correct startup fuel requirement.

If flexible lines are used between this injection pump and the injectionnozzles, a slight rotation of the pump body relative to its mountingwill result in an advance of injection if rotated one way and aretarding if rotated in the other direction. As the fuel injection linesare very small, if grouped together such a slight rotation of the pumpas is needed might be accomplished wtihout using flexible non-metalliclines.

1. A fuel injection device combining the functions of both a transferpump and a fuel injection pump in a single structure and including incombination: a hollow pump housing having a fuel inlet means, fuelinjection outlet means, and an excess-fuel-return outlet; a platemounted in said housing and dividing its interior into a pump chamberbelow said plate and in communication with said fuel inlet means andsaid fuel-injection outlet means, and a surge chamber above said plateand in communication with said excess-fuel-return outlet, said platehaving intake means and spill ports therethrough; a ring gear mounted tosaid housing and defining the outer periphery of said pump chamber, withan upper surface in contact with said plate, said ring gear having teethwith crests alternating with tooth cavities, said intake means in saidplate opening adjacent and just radially inside some of said toothcrests, said housing inlet means including inlet ports located justradially inwardly from and closely adjacent the crests of some teeth ofsaid ring gear in vertical alignment with said intake ports, saidhousing fuel-injection outlet means including discharge ports in some ofsaid teeth cavities between said inlet ports, said spill ports openinginto the same cavities but being spaced apart a short horizontaldistance from said outlet means; a rotatable shaft in said housing belowsaid plate; and a pinion gear mounted eccentrically on the upper end ofsaid shaft in said pump chamber in mesh with said stationary gear, withan upper surface in contact with said plate and a lower surface incontact with said housing, whereby as said pinion gear moves around insaid ring gear it sucks fuel in through each inlet port into said pumpchamber where moving out of mesh and simultaneously expels fuel throughsaid intake means into said surge chamber where moving into mesh, oncesaid fuel chamber contains some fuel successively, and expels fuelthrough said spill ports and said outlet ports where moving into mesh.

2. The device of claim 1 having means for rotating said plate relativelyto said stationary ring gear for varying the porting area of said spillports by closing portions thereof against said stationary ring gear, soas to vary the relative proportions of fuel expelled through said spilland outlet ports.

3. A fuel injection device combining the functions of both a transferpump and a fuel injection pump in a single structure and including incombination: a hollow pump housing having a fuel inlet means,fuel-injection outlet means, and an excess-fuel-return outlet; a platemounted in said housing and dividing its interior into a pump chamberbelow said plateand in communication with said fuel inlet means and saidfuel-injection outlet means, and a surge chamber above said plate and incommunication with said excess-fuel-return outlet, said plate havingintake ports and spill ports therethrough, said ports being arranged ina circle and alternating spill and intake ports; a stationary ring gearmounted to said housing and in said pump chamber, with an upper surfacein contact with said plate, said ring gear having teeth alternatingcrests with tooth cavities, said intake ports lying just .above andradially inwardly from the crests of some teeth and spaced no closerthan every third crest, said housing inlet means including inlet portsopening into said pump housing just below said intake ports, saidfuel-injection-outlet means including discharge ports in tooth cavitiesspaced apart by at least three teeth, located betweensaid inlet portsand the same cavities into which said spill ports open, said spill portsbeing spaced horizontally from said discharge ports; a rotatable shaftin said housing below said plate; a pinion gear mounted eccentrically onthe upper end of said shaft in said pump chamber in mesh with saidstationary gear, with an upper surface in contact with said plate and alower surface in contact with said housing, whereby as said pinion gearmoves around in said ring gear it sucks fuel in through each inlet portinto said pump chamber while moving into mesh and simultaneously expelsfuel through said intake ports into said surge chamber, while moving outof mesh, once said fuel chamber contains some fuel, and expels fuelthrough said outlet ports and said spill ports; a check valve for eachsaid inlet port in said inlet means; a check valve for each said intakeport; a check valve for each said outlet port in said fuel-injectionoutlet means; and a check valve for said excess-fuel-outlet.

4. The device of claim 3 having means for rotating said plate relativelyto said stationary gear for varying the amount of porting afforded bysaid spill ports from their cavities by closing portions of said spillports against said stationary ring gear. r

5. A fuel injection device combining the functions of both a transferpump and a fuel injection pump in a single structure and including incombination: a hollow pump housing having a fuel inlet means,fuel-injection outlet means, and an excess-fuel-return outlet; a platemounted rotatably in said housing and dividing its interior into a pumpchamber below said plate and in communication with said fuel: inletmeans and said fuel-injection outlet means, and a surge chamber'abovesaid plate and in communication with said excess-fuelreturn outlet, saidplate having intake ports and spill ports therethrough, said ports beingarranged in a circle and alternating spill and intake ports but .atdilferent radial distances from the center; a stationary ring gearmounted to said housing and in said pump chamber, with an upper surfacein contact with said plate, said ring gear having teeth alternatingcrests with tooth cavities, said intake ports in said plate lying justabove and opening into said pump chamber at the crest of every thirdtooth, said housing inlet means including inlet ports opening into saidpump housing at the crest of every third tooth in vertical alignmentwith said intake ports, said housing fuel-injection-outlet meansincluding discharge ports located in the bottom of the every thirdcavity midway between the crests where said intake ports open said spillports opening into the same cavity but at a different location therein;a rotatable shaft in said housing below said plate; a pinion gearmounted eccentrically on the upper end of said shaft in said pumpchamber in mesh with said ring gear, said pinion gear having fewer teeththan and in hunting relation with said ring gear, with an upper surfacein contact with said plate and a lower surface in contact'with saidhousing, whereby as said pinion gear moves around in said ring gear itsucks fuel in through each inlet port into said pump chamber adjacentsome crests and simultaneously expels fuel through said intake portsinto said surge chamber adjacent other crests, once said fuel chambercontains some fuel, and expels fuel through said outlet ports and saidspill ports; a check valve for each said inlet port in said inlet meansyielding to and opening under suction on its inlet port; a check valvefor each intake port yielding to and opening under pressure; a checkvalve for each said outlet port in said fuel-injection outlet meansyielding to pressure in said outlet port; a check valve for saidexcess-fuel-outlet yielding to pressure in said surge chamber; and meansfor rotating said plate relatively to said stationary gear for varyingthe porting areas of said spill ports into their cavities by closingportions thereof against said stationary ring gear and thereby varyingthe relative proportions of fuel expelled through the spill ports andoutlet ports.

6. A fuel injection device combining the functions of both a transferpump and a fuel injection pump in a single structure and including incombination: a hollow pump housing, a plate in said housing dividing itsinterior into a pump chamber below said plate and a surge chamber abovesaid plate, said plate having pressure operated, normally closed intakemeans and spill ports therethrough, said housing having a stationaryring gear defining an outer peripheral portion of said pump chamber andin contact with said plate, said gear having teeth with crests andcavities, said intake means opening into said pump chamber adjacent someof said crests; excessfuel-return outlet means responsive to pressure inand leading from said surge chamber; fuel inlet means opening underpartial vacuum conditions into said pump chamber adjacent the crests ofsome teeth of said ring gear; pressure-responsive fuel-injectionoutletmeans including outlet ports leaving said pump chamber from someof said cavities, said spill ports opening into said pump chamber in thesame cavities as said outlet ports but spaced apart therefrom; and apinion gear mounted eccentrically in said pump chamber in mesh with saidstationary ring gear and in contact with said plate, to draw in fuelfrom said fuel inlet means where moving out of mesh adjacent a cresthaving associated fuel inlet means, to force draWn-in fuel into saidsurge chamber through said intake means where moving into mesh adjacenta crest having associated intake means, to force fuel out into saidfuel-injection outlet means where moving into mesh in a cavity havingassociated fuel-injection outlet means, and to send excess fuel intosaid surge chamber through said spill ports Where initially moving intomesh in a said cavity having associated fuel-injection outlet means.

7. The device of claim 6 wherein said intake and inlet means arepositioned adjacent the same crests.

8. A fuel injection device combining the functions of both a transferpump and a fuel injection pump in a single structure and including incombination: a hollow pump housing having a stationary ring gear havingteeth with crests and cavities; a plate in said housing in contact withsaid gear and dividing the interior of said housing into a pump chamberpartly defined by said gear and a surge chamber, said plate havingpressure actuated intake means and spill ports therethrough, said intakemeans opening into said pump chamber adjacent some of said crests;excess-fuel-return outlet means responsive to pressure in and leadingfrom said surge chamber; fuel inlet means opening under vacuumconditions into said pump chamber adjacent the crests of some teeth ofsaid ring gear; pressure-responsive fuel-injection outlet meansincluding outlet ports leaving said pump chamber from some of saidcavities, said spill ports opening into said pump chamber in the samecavity as said outlet ports but spaced apart therefrom; and a piniongear driven eccentrically in said pump chamber and in contact With saidplate and driven within and in engagement with said ring gear, to drawin fuel from said fuel inlet means while moving out of mesh adjacent acrest having associated fuel inlet means, to force drawn-in fuel intosaid surge chamber through said intake means while moving into meshadjacent a crest having associated intake means, to force fuel outthrough said fuel-injection outlet means while moving into mesh in acavity having associated fuel-injection outlet means, and to send excessfuel into said surge chamber through said spill ports during an initialportion of moving into mesh in a said cavity having associatedfuel-injection outlet means.

9. A pumping device combining the functions of both a transfer pump andan injection pump in a single structure and including in combination: ahollow pump housing with a stationary ring gear having teeth with crestsand cavities; closure means in said housing dividing its interior into apump chamber on the same side as said gear and a surge chamber on theother side, said closure means having intake means therethrough openinginto said pump chamber adjacent some of said crests; excess returnoutlet means responsive to pressure in and leading from said surgechamber; inlet means opening under suction into said pump chamberadjacent some of said crests; pressure-responsive injection outlet meansincluding outlet ports leaving said pump chamber from some of saidcavities; and a pinion gear driven eccentrically in said pump chamber inmesh With said stationary ring gear, to draw in liquid from said inletmeans, to force liquid into said surge chamber through said intakemeans, and to force liquid out into said injection outlet

